Re: [patch 1/3] memcg: prevent endless loop when charging huge pages

[Minchan Kim <minchan.kim@gmail.com>]

On Mon, Jan 31, 2011 at 11:03 PM, Johannes Weiner <hannes@cmpxchg.org> wrote:
> The charging code can encounter a charge size that is bigger than a
> regular page in two situations: one is a batched charge to fill the
> per-cpu stocks, the other is a huge page charge.
>
> This code is distributed over two functions, however, and only the
> outer one is aware of huge pages.  In case the charging fails, the
> inner function will tell the outer function to retry if the charge
> size is bigger than regular pages--assuming batched charging is the
> only case.  And the outer function will retry forever charging a huge
> page.
>
> This patch makes sure the inner function can distinguish between batch
> charging and a single huge page charge.  It will only signal another
> attempt if batch charging failed, and go into regular reclaim when it
> is called on behalf of a huge page.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>

-- 
Kind regards,
Minchan Kim